Chaste Berry Extract (Agnus castus) (fruit)

Vitex agnus-castus is the scientific name for the plant commonly referred to as chasteberry, Vitex, or Monk's pepper. Chasteberry is a member of the Verbenaceae family. This medicinal plant is native to the Mediterranean and Central Asia where it has a long history of use by herbal healers, including Hippocrates and Dioscorides. Ancient uses for chasteberry included birth control and suppression of libido, especially in monks.

Botanically, chasteberry plants appear as a deciduous perennial shrub, which grow to heights between 6 and 25 feet. The fruit of the plant is primarily used and appears as tiny black peppercorns, possessing a pepper-like aroma and flavor. The leaves are occasionally used medicinally and appear as 2 - 6 inch long leaflets that are dark green above and gray underneath. Slender spikes of lavender/blue flowers are sometimes used in medicines as well.

Chasteberry contains a number of active constituents, most of which are found in other plants. The only unique component that has been identified solely in chasteberry is an iridoid glycoside called agnuside. Other active constituents include flavonoids (castican, orientin and isovitexin); iridoid glycosides (aucubin and eurostoside); volatile oils (0.8 - 1.6%): terpenoids (cineole, sabinene, limonene, camphene), a- and b-pinene; and 3-ketosteroids; likely progesterone, and 17-hydroxyprogesterone.

Much of the research on the pharmacology of vitex focuses on the effects of this plant upon the pituitary gland. Studies have shown that vitex can inhibit prolactin production by binding to dopamine receptors found in the pituitary gland. [4, 5] Inhibition of prolactin synthesis effects the female reproductive system by enhancing growth of the corpus luteum, thereby increasing progesterone levels. [6] Furthermore, vitex has also demonstrated effects on anterior pituitary production of luteinizing hormone (LH) and follicle stimulating hormone (FSH). Vitex increases LH production, inhibits FSH production, resulting in a relative increase in progesterone and a decrease in estrogen in women. In men, it appears that testosterone is decreased.